


Then Comes Baby In The Baby Carriage

by themystery424



Series: I'll Love You Even When You Forget My Name [10]
Category: Undertale, Undertale (Video Game)
Genre: Babies, GUYS THERE ARE BABY SOULS, M/M, Souls, The Void, Twin skelebros, the creation of our skelebros, tiny little guys
Language: English
Status: Completed
Published: 2017-06-01
Updated: 2017-06-01
Packaged: 2018-11-07 14:49:59
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 4,727
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11061252
Author URL: https://archiveofourown.org/users/themystery424/pseuds/themystery424
Summary: There are children on the way! Gaster and Grillby decide they want to have a child of their own, and go through the long and complicated process of having a child. They're so excited to be parents! The creation of Sans and Papyrus, and the delight of proud dads W.D. Gaster and Grillby.(guys I'm so sorry if this is confusing. I got headcannons about how monster-children are born, and I tried to explain that, while carrying the plot, while also trying to make this adorable. <3 expect more baby orientated fics after this :) another update to the soulmate series)





	1. Let's Begin

**Author's Note:**

> Gaster and Grillby refer to the baby soul as 'they/them' or 'it' until the two of them are sure of the gender.  
> The soul refers to himself as the correct gender, because of course he is a soul, he knows. Just in case that gets hard to follow.

Grillby felt Gaster tense in his hold. His question was a shocking one, yeah. They had never discussed children before. He wondered if Gaster didn’t want kids, and that’s why he’d never brought it up. At the same time, Gaster was the last skeleton alive. He _must_ want children. The chance that their child would be a skeleton, and carry on his species _had to_ outweigh any fears about parenthood. Grillby felt twists of magenta shoot through his flames, nervousness filling his body.

“You want a child with me?” Gaster asked, finally responding. Grillby nodded. “... But, why?” Gaster asked, sitting up and moving away from Grillby some. The look on his face, and in his eyes. Grillby recognized it. It was the look Gaster had when he was collecting data for an experiment. It was a little unnerving.

“I want to have a child with you, Gaster, because I love you. And I like the idea of a monster running around with fragments from our own souls in them.” Grillby replied. “I like the idea of raising a baby with you. I like the image of you holding a baby skeleton in your arms, or maybe in the lab with you one day, or in the bar with me, learning about our different passions. I want to our family to grow.”

Gaster’s look melted immediately, and his eyes started glowing a faint purple. “You want a baby skeleton?”

“Well,” Grillby blushed. “I think a mini you would be adorable.”

“Aw Grillby…” Gaster smiled. Then he sighed. “Grillby, the work. We would have to cut down on hours, and where would we live! This place isn’t big enough for a family.”

“There’s a house just down the street, with a nice living room, a smaller kitchen than I’d like but it has two bedrooms upstairs.” He said. “I’ve been looking into it.”

Gaster sighed again, running his hands over his skull. Grillby followed the gaping holes in the center of his hands, his soul pounding. He didn’t know what he’d do if Gaster said no to kids all together.

“It’ll be painful.” Gaster muttered.

“Yeah, but it’ll be worth it.” Grillby urged, sliding closer to his husband.

Gaster looked up into his gold eyes. “How do we even… break off a piece of our souls? I was never taught how to do that in the first place.”

“I have no idea. But we’ll figure it out.” Grillby hesitated. “That is, if you want to do this.”

Gaster smiled, reaching up and pulling Grillby’s head down for a soft, slow kiss. Grillby’s flames sparked happily, and he pulled Gaster closer, holding him tightly. “Of course I want to have a child with you.” Gaster whispered once they parted. “I love you so, so much.”

Gold flames erupted from Grillby. “I love you too, Wingdings Gaster.” He grinned. “We’re going to be parents. We’re going to be parents! Can you believe it?” Gaster laughed and held his husband’s hands.

“How about we go and make a new soul before we get all excited?” He beamed. Grillby  huffed.

“If you insist.” He smiled, standing and offering his hand to Gaster. Gaster didn’t take his hand, but sprinted up to their room, disappearing and reappearing at the top of the stairs. “Hey! No teleporting in the house, Gaster!”

“It’s not teleporting! It’s finding shortcuts!” Gaster yelled back as Grillby ran after him, the skeleton sprinting the rest of the way to their room.

“It is teleporting! I don’t care what you call it, it’s definitely teleporting!” Grillby took the stairs two at a time, running into their shared bedroom. He was met with the sight of Gaster struggling to get his turtleneck off, and the fire monster couldn’t help but laugh. “Is your shirt caught on your head, Gaster?”

“How about instead of laughing at me, you help?” Gaster suggested, agitated.

“Nah. I think you can do it yourself.” Grillby grinned, beginning to take off his own top layers. “You do it yourself any other night.” Gaster groaned and kept fighting with his shirt. Grillby’s grin slowly settled into a content smile. He was going to have a child with the monster who he loved with his entire soul.

 

Gaster’s mind was racing. He was thinking of every single thing he’d learned about having a child. It was simple enough. Two monsters took a shred of their souls and fused them together. The two colors would fight for dominance, which decided which parent the child would most be like. In this case, if the soul turned completely gold, it’d be a little fire monster. If it turned purple, then it’d be a little skeleton. Once that was decided, it’d turn white, and grow and form into the heart-shape all souls were. Over time, the soul would turn into the color they would have for the rest of their lives. After that, their physical mass would start to grow around the soul. Then, then there’d be a baby.

It was so much more complicated when put on paper, Gaster noticed. He finally got his turtleneck off, just to met with the sight of his husband sitting on the bed. Grillby was watching him, a soft smile on his face. His flames were burning low, but were still gold. Gaster blushed.

“What’s that look for?” He asked.

“You’re just… perfect.” Grillby told him. Gaster blushed darker and got on the bed. “Ready?”

“Yeah.” Gaster nodded, putting his hand to his ribcage. He pulled his soul forward, it floating in his hand. Grillby mirrored the action, his gold soul burning brightly above his hand. Gaster looked between the two souls. “So… How do we do this?” He asked.

“I was always told that it’s a matter of letting your mind go blank, and know what you want. It definitely will hurt, though, but apparently as long as you stay focused it won’t be as bad.”

Gaster frowned at the confusing instructions. His frown disappeared and was replaced by awe as he watched his husband slowly pull a piece of his soul apart. Grillby’s face twisted a bit, confirming the pain that would accompany with ripping a piece of his soul off. If Grillby could do it, Gaster could too.

The skeleton focused on his soul, on separating a piece from himself. It did start to tear, making pain sear through him. A whimper escaped his mouth, and the shift in weight on the bed signalled Grillby moving closer. This presence was a comfort, though the pain was still there.

“It’s okay, Gaster.” Grillby whispered. “Try not to think about it.” Gaster nodded a few times, still tugging and pulling the smaller piece off. Finally, there was a shard. Grillby took the smaller piece, Gaster returning his soul back to his chest. He watched as his husband pressed the two shreds of soul together.

Immediately the form took to hovering in the air on its own, doubling in size as gold and purple swirled around. The two colors overlapped and fought for surface area, making Gaster grin. It was beautiful, watching the colors fight for dominance. Sparks flew off from every direction as the two colors twisted around each other.

Gaster laid back in Grillby’s arms, both monsters watching with content smiles on their faces.

 

“What if it lands in exactly half?”

Grillby looked down at his husband. “Half gold, half purple?” Gaster nodded. “Well, I suppose then we’ll have a skeleton who is also on fire.”

“That sounds like a handful.” Gaster sighed. “Maybe this was a bad idea. Is it too late to change our minds?”

“Yes, it’s too late. And that’s not going to happen. Our baby will be a skeleton or a fire monster.” Grillby assures him. Finally, the entire soul flashed purple before settling into the bright white color. Gaster squealed, making Grillby laugh.

“A skeleton! A baby skeleton Grillby! I can’t believe it!” Gaster exclaimed, holding onto Grillby tightly. “I… I won’t be the last one anymore.” He whispered. Grillby held him tightly as he rubbed his back.

“I love you, Windings.” He whispered. “I’m so happy we’re going to have a baby skeleton.”

“I love you too. And, me too.” Gaster yawned. “Night, Grillby.” Grillby looked at Gaster, who immediately dozed off to bed. Then he looked at the tiny white soul, floating in the air. They didn’t have anywhere to put it yet. They’d need to get a crib for sure. For now, Grillby cupped the soul in his hand and pulled it close. The rounded white blob snuggled close into the flames, keeping warm, and Grillby smiled. It didn’t take long for the fire monster to fall asleep himself.


	2. Troubled Soul

**Summary for the Chapter:**

> A reason as to why Gaster remembers resets.

Gaster stared at the readings in front of him. It made sense. The reason the excess magic flowed to where the Core was now built was because there was a crack between the Underground and the Void. The magic that the Core didn’t use as fuel flowed into the Void, which happened to be at its center. And when near the Core’s center, it was possible to absorb some of the Void itself. Gaster looked down at his hands, looking at the gaping holes they now had. It was definitely possible that it had been energy from the Void that had started to eat at him when he’d passed out in the center that night.

And it was possible that his soul had absorbed some of the Void too, which then made sense that he’d remember resets. Then he remembered the little white soul floating in the crib at home. He remembered the sliver of his own soul in that newly formed soul. Gaster looked down towards his rib cage. A sliver of soul that probably carried traces of the Void in it. Hopefully their child wouldn’t remember resets. Hopefully Chara wouldn’t reset anymore.

Then Gaster laughed, and he laughed hard. The human had reset at least twice since they had done it the first time. Thankfully, no more monsters came stumbling into shops looking to boost their HP. Gaster could only assume Chara was using their resets to avoid anyone remembering the damage they had done. A step up, he supposed. Still, he feared for Asriel. He feared for his unborn child. He feared for monsterkind on the whole.


	3. A Soul Developing

**Summary for the Chapter:**

> The baby soul is growing! And Gaster and Grillby are excited- mostly. Until it gets boring. This is not how to parent. Pay more attention to your baby soul

At first, it was really interesting. Gaster and Grillby would spend hours at a time watching the little white soul bob around, form, unform, spread thin and curl up on itself again. Though, after awhile, it was no longer such a novel. They got up, they went to work, they came home, watched it for twenty minutes, and went to bed. It was just a soul now.

Gaster was the one who noticed when it finally stopped changing shape. He’d pulled Grillby over and smiled, watching the newly formed heart bounce back and forth in place. “Look at that.” He whispered. “The soul is growing so fast… the physical matter shouldn’t be too far behind.”

“There’s still a little while to go.” Grillby chuckled as the heart did a little spin. “The soul still has to pick a color, you know?” Then he paused. “What color do you think it’ll be?”

“I don’t know.” Gaster thought. “I was hoping for a cool color. Like green, or maybe indigo.” Grillby looked at his husband, noticing a small blush on his cheeks.

“Or, purple, perhaps?” He teased, and Gaster huffed, his blush darkening.

“Well it is possible!” The skeleton exclaimed. “What about you? What color do you think it’ll be?”

“Honestly? I don’t know, or really care.” Grillby smiled. “I’m just happy we’re going to have a little skeleton of our own to hug and hold and care for.” Then he paused. “Gaster, did you ever tell the Queen or the King that we’re expecting?”

Gaster didn’t respond, and Grillby frowned. Finally Gaster cleared his throat. “I was going to get to it.”

“Gaster! You know the Queen at least would want to know!” Grillby scolded.

“Yes, yes I know. I know. I’ve just been so busy at work, it slipped my mind.” Grillby was still frowning. He went downstairs and grabbed his cell phone. On his way back to their room, he dialed the number for Toriel. He had the phone on speaker, and Gaster eyed the phone suspiciously.

“Hello? This is Toriel.” Toriel’s sweet voice came through the other end. Gaster’s eye-sockets widened and he shook his head.

“Hi Toriel. This is Grillby.” The fire monster carried on. “I was just calling with some news to share with you.”

“Some news? How interesting! I certainly hope it’s good news! Is Gaster with you?”

“Yeah, he’s here. Normally I’d make him tell you what I’m going to tell you, but unfortunately you wouldn’t be able to understand him through the phone.”

“Yes, it is a shame that I can’t yet. He keeps telling me that soon he’ll install his translator onto my phone. Unfortunately he keeps saying he’s busy.” Grillby glared at Gaster again, who blushed and looked away.

“I’ll get right on him about that. He really needs to keep better contact with you.”

“It would be nice, but he is his own monster. I cannot make him do anything.”

“I can’t either, but I’ll certainly give it a try.” Grillby hesitated then cleared his throat. “Toriel, would you like to hear some exciting news?”

“Oh yes! Of course!” Toriel exclaimed happily.

“Gaster and I are expecting a child.” Grillby told her simply, and she squealed in delight from the other end. Gaster smiled softly at the sound of her excitement, and Grillby’s flames burned a bright gold.

“Oh how exciting! How far along is the child? Not too far I hope.”

“Pretty far, actually.” Grillby sighed. “I thought Gaster had told you already. The soul has already taken on its permanent shape.”

“I see.” She sounded slightly disappointed, and Grillby gave his husband a pointed look, hoping to convey the notion that he was never going to wait till the last second to tell the queen again. “Thank you for sharing your happiness with me! I cannot wait. Oh, is the child going to be a fire monster or a skeleton?”

“A skeleton.” Gaster and Grillby said at the same time. “A baby skeleton.” Grillby repeated. “We’re both extremely excited. Next time, Toriel, don’t worry. We won’t leave you out of the loop again.”

“I appreciate that, Grillby. Thank you for informing me. Keep me updated on your little soul’s progress!”

“Definitely! Nice talking to you, Toriel.”

“Same to you, Grillby. Have a nice evening, boys.” And she hung up, with a click.

“I would have done that eventually.” Gaster huffed.

“Yeah, I totally believe you. By the way, you’re installing the translator on her phone the next time we visit.” Grillby crossed the room to the scientist, wrapping his arms around his middle. He pulled him close to his body, wanting to keep him warm. “Understand?”

Gaster nuzzled into his neck, eyes closing in bliss as he snuggled into the flames. “Yes dear.”

 

Grillby was the one who noticed when the soul adopted its permanent color. He had been getting ready for work when he happened to glance over at the crib in the corner of their room. The heart was shimmering with a light aqua blue color. He grinned and grabbed his cell phone, calling his husband who was already at work.

“Hello?” Gaster responded, sounding distracted.

“Gaster, my love, I have some news for you.”

“Yes?” Gaster still sounded distracted, and Grillby huffed.

“Stop doing science Gaster! Listen to me.”

Gaster groaned, but Grillby heard him put his pencil down. “Okay! You have my undivided attention.”

“The soul is blue. A pale blue.” Grillby heard Gaster gasp.

“Really? The soul is blue! Oh… oh my… Grillby, do you know what this means?”

“Yes, I do.” Grillby smiled.

“We’re so close to the physical mass stage! It won’t be long now and we’ll be holding the little skeleton in our arms! We’ll be able to teach our child so many wonderful things! How to cook, science, different attacks! Oh! Do you think the little skeleton will be able to learn fire attacks, since they have part of your soul in them? Or only skeleton attacks? Either way, I can’t wait to show the little one how to summon Gaster blasters and-”

“What are Gaster blasters?” Grillby asked, confused. “I’ve never seen you use an attack like that.”

“Oh, it’s this new attack I’ve been developing. It’s been a challenge, but I’ve enjoyed it! The blasters are super powerful, and I can’t wait to show them off!”

Grillby laughed softly and shrugged. “I guess we’ll just have to see if they take to it. Alright, I’ll let you get back to work. I’ll see you tonight, Wingdings.”

“I’ll see you tonight, dear Grillby. Have a great day at work. I love you.”

“I love you too.” Grillby replied. Gaster hung up and sighed. He looked again at the readings again. No, there was no mistake. His soul was tainted with the Void. It was deep, at the center of his soul and rarely surfaced. Gaster recalled when he’d torn the piece of his soul off for the creation of his child. He had pulled it from deep within his own soul. That meant there was a good chance there was Void in his child’s soul as well.

Gaster sighed. He returned to his notes and began to calculate what he’d need for an antidote. He wouldn’t curse his child to a life of knowing resets. Not if he had any say in the matter.

 

Neither of them noticed when the soul shrank. Not only shrank, but shrank considerably. It lost three quarters of its original mass. But the tiny, blue soul didn’t mind being so tiny. The blue soul did wish that his parents would notice that he spent a lot of time at the bottom of his crib. Because the mass of soul that had separated from himself wasn’t gone. It was at the bottom, barely alive and glowing. The blue soul tried to nudge the mass together, to take form, but it didn’t want to.

The blue soul was having none of that. He continued to nudge the unformed soul together. Why wouldn’t his parents notice this new soul was here? Why wouldn’t they look? Well, they would today, the blue soul decided. He wasn’t gonna let the new soul fizzle out and disappear. This new soul was his sibling, a part of himself.

The blue soul waited, watching for his parents to come home. The one that was always on fire came home first, like always. The blue soul swirled around, hoping to get his attention. The fire parent wasn’t paying attention. The blue soul noticed when his other parent came home, the one that was bones. The boney parent laid down next to the fire parent, and the two began to make noises at each other that the blue soul didn’t understand.

He began to float all around, swirl, flip, anything to get their attention. Still, they continued to make noises at each other. They didn’t seem to notice the little blue soul at all, and it was awful. The blue soul looked down at the mass of the new soul. It wasn’t glowing as much anymore, and the blue soul panicked. How was he going to get the attention of the parents? Why weren’t they watching?

Then the blue soul got a great idea. Well, it was a scary idea, but it was an idea. Hopefully it’d get the attention of the fire parent or the boney parent. He dived off of the side of the crib, heading straight for the floor. Right before he hit the floor, he felt something hold onto him. It was like being held by his parents, but closer. Much more intimate and relaxing. The blue soul almost forgot what he was doing, then he noticed that his parents were getting off the bed and walking over, the boney parent’s hand glowing blue. Now he could show them his sibling.

 

Gaster stared at the blue soul suspended in his blue magic. He could feel his own soul pounding, not understanding why his child would dive out of their crib. No, his crib. Holding onto the soul, he could now tell the gender of their child, which did make him feel extremely happy. It didn’t override his worry though, and he looked at his husband.

“What _was_ that?” Grillby asked.

“I have no idea.” Gaster got up and walked over to the baby soul, raising it using magic and holding it in his physical hands. “I do know the gender now.” He smiled at Grillby. “We’re having a boy.”

“You should have done that earlier.” Grillby grinned. “Now we can decorate the nursery when we move into the new house.”

“Oh, did you put a down payment on the new house?” Gaster’s eyes glowed purple.

“I did.” Grillby said proudly. “I actually remembered to do that.”

“Oh good! We can start moving in at once-” Then Gaster noticed the blue soul falling again, and caught him quickly. “Goodness! You need to stop doing that!” He lifted the blue soul back up into his hands again. “What’s gotten into you?” The blue soul started to point at the crib. Gaster, confused, walked over to the crib and looked in. “Oh… Grillby, come here.”

Grillby walked over to the crib and looked in. “Is that… another soul?” He glanced at Gaster’s hands, and noticed that the original soul was now a lot smaller. “Gaster, look at him.” Gaster looked down at his own hands.

“Oh my… how did this happen? What is happening. I-” Then he stopped, and his eyes lit up. “Grillby… are we having twins?”

Grillby leaned over and scooped the mass of soul up in his hands, holding it close to himself. “Twins? Isn’t that, impossible?” He asked. Gaster watched as the blob of soul started glowing brighter, just with Grillby’s touch. He reached out and caressed the new soul himself. It glowed brighter still, and for the first time since Grillby picked up the new soul, it moved on its own and started to take shape. The blue soul moved over to the new soul and nuzzled against it encouragingly.

“It’s supposed to be. Souls don’t usually split on their own.” He smiled. “But ours did. We’re going to have twins! Twin skeletons! Isn’t that great, Grillby? Two little baby skeletons for us to hold and take care of!”

“Yeah… do you think we’ll have enough room in our new place?” Grillby asked, looking away from the tiny souls in their hands.

“Of course! Our twins can share a room. Already this little guy loves the new one. Enough so at least that he wouldn’t let the new soul just die!” Gaster was overjoyed, eyes glowing almost brighter than the happiest day of their lives- their wedding day. Grillby grinned and pulled Gaster close, the two souls between them hovering close to one another.

“I’m so happy, Wingdings.” Grillby said, kissing him softly. Gaster immediately returned the affection, eyes closing in bliss. Grillby pulled his lips back half an inch. “I love you so, so much. I can’t wait to hold these two in our arms.”

“Me neither.” Gaster sighed contently. “Me neither.”


	4. AND THEN THERE WERE TWO BABES

**Summary for the Chapter:**

> BABIES ARE BORN

The blue soul had waited until the orange soul was ready before he decided to start forming any bones. The two aged at the exact same rate, the blue soul never getting ahead of the orange soul although he was older. They formed their rib cages first, then pelvic bones, legs, arms, vertebrae, and lastly, their skulls. During that time, the blue soul had noticed that the orange soul was male, like himself. They were brothers.

The day the blue souled skeleton could open his eye sockets, having never seen anything before, he was terrified. He was scared of everything he saw, and began to whimper in fear. His parents were still sleeping in bed with each other, snuggled up and happy. When he looked over to his left, he could see his brother was also there, sleeping. His brother’s eyes opened slowly at the blue soul’s whimpering, and he looked confused.

The orange souled skeleton wasn’t scared by the world he saw. He saw his parents sleeping on the bed, and was excited. He saw his brother, who had been so kind to him, encouraged him on, and waited for him. He started to giggle and babble at his brother. The blue souled skeleton looked at him in confusion, but his fear was waning away. The smaller skeleton began to giggle along with his brother, moving his little arms around. Then his brother started to as well, and they babbled at each other. The blue souled skeleton didn’t mind that his brother was so much louder than himself. It was nice.

 

When Grillby woke up, he thought at first that it was his alarm clock going off. There was so much noise in the bedroom he and Gaster shared, more than there had ever been. He and Gaster had only been living in the new house a few weeks, and the fire monster was still adjusting to the new environment, which meant he hardly slept at all.

Now he was up far earlier than he needed to be, and his flames burned low with annoyance. Until he realized what he was listening to.

Grillby jumped out of bed, nearly falling face first against the ground in excitement. “Gaster!” He shouted, startling everyone in the room, including the brand new babies babbling in their shared crib. The babies went quiet, and thankfully they didn’t start crying. “Gaster, Gaster wake up. Wake up.” Grillby shook his husband gently. Gaster groaned and opened his eye sockets.

“Wha-what is it, Grillby?” He murmured sleepily. “Was going on?”

“The babies! They’re done growing!” Grillby grinned. “You have to see them. Come on!”

“What? Grillby.” Gaster sat up, rubbing his eyes. Then it sunk in. “They’re done growing?!” He got up at once, and the two proud parents ran to the edge of the crib. The two tiny skele-babies stared up at them with wide, gaping eye sockets, their little pinpricks of white in the center of their eyes gleaming brightly with fresh life. “Oh… you little sweethearts.”

Gaster bent over and picked up the smaller of the two, a smile engraved into his features. He cradled the little skeleton, smiling wide at how happy he looked. Grillby picked up the bigger one, cooing softly. His gold flames were burning brightly as he held one of his sons close to his chest. The little baby’s eyes began to glow orange at how close he was to one of his dads, taking comfort in the flames.

“Gaster. His eyes are glowing.” Grillby whispered, on the verge of tears he was so happy. Gaster looked over, and couldn’t help himself. Tears escaped the corners of his sockets, and he looked down at the baby in his arms. The baby was smiling wider, if that was possible. His left eye was glowing blue. Gaster frowned some.

“Grillby, I think… I think his soul breaking off for his twin may have caused some kind of growth stunt…” He whispered.

“It doesn’t matter.” Grillby reassured him, leaning over and kissing the top of his husband’s skull. “We’re going to love him all the same.”

“AGOOOO.” The skeleton in Grillby’s arms chimed in.

“heeeee.” The little one in Gaster’s arms replied, and Gaster choked on a laugh.

“What? Can you see it? Their fonts?” Grillby asked excitedly. “You said you’d be able to sense them, when they made noise.”

“Ye-yeah.” Gaster nodded, his smile stretched as wide as it could across his face. “O-oh Grillby… They in-inherited their father’s silliness in font choices.”

“Oh?” Grillby chuckled. “Enlighten me dear, what are our children’s names?”

“Well… right there, in your arms,” Gaster took a deep breath, still smiling as wide as he could. “Is our little Papyrus. And here,” Gaster brought the smaller skeleton to his face, gently nuzzling him with his teeth in an effort of giving his baby a kiss on the top of his skull, “And here we have Comic Sans.”


End file.
